Geochronology Lab

Our instrumentation is in the process of being decommissioned. We have funding for a new NG MS, but it will not be operational for at least 1.5 years.

The Geochronology Laboratory at UAF conducts research in determining the ages of rocks and minerals using the 40Ar/39Ar step-heating dating method. Major areas of research emphasis include determining the tectonic history of Alaska and adjacent Russia, determining the relationship between plutonism and ore mineralization and determining the eruptive history of Alaska's volcanoes.

The laboratory has two mass spectrometer systems, a Nuclide system installed in 1970 with an on-line extraction furnace and a VG3600 laser system installed in 1994. We completed over 2000 mass spectrometry analyses on 143 samples in 1993 and 2500 mass spectrometry analyses on 158 samples in 1994 on the Nuclide mass spectrometer system. In 1994 we completed over 1200 mass spectrometry analyses on the newly installed laser system. Many of these analyses were done on research grants and internally supported projects discussed below while others were on externally supported contracts and in support of student theses.

Corporations which supplied support for the geochronology laboratory in exchange for age analyses in 1993 and 1994 include: Placer Dome Inc., ASA Inc., Ryan Lode Mines Inc., Fairbanks Gold Mining Inc., Arco, and Chevron Minerals Division. Universities which provided contract support or collaboration include Michigan State University, Beloit College, Stanford University, University of Pittsburgh, University of Witwatersrand in South Africa, and Lulea University in Sweden. Supporting government agencies include the Alaska Division of Geological and Geophysical Surveys, the U.S. Geological Survey, U.S. Bureau of Land Management and the U.S. Bureau of Mines.

Student thesis work involved investigations of the plutons of the northeastern Brooks Range, the mineralization in the Fairbanks district, the history of the Southwest Nevada Volcanic Field, the igneous and metamorphic rocks in Russia, mineralization in southern Africa and Australia, and the thermal history of the McKinley pluton.

For more information contact

Sean Regan at 907-474-5386


The Geochronology Laborary is also located in the Reichard Building, third floor, on the UAF campus. It determines the ages of rock and minerals.